The Hidden Costs of Virtualization By Dave Leonard published: Thursday, February 08 2007
By Dave Leonard, CTO Infocrossing
We are seeing virtualization across all platforms: AIX, Solaris, Intel, AMD. Of course, mainframes always had virtualization. VMware ESX is the predominant platform currently in the Intel/AMD space, but new entrants such as XenSource are making inroads, and the 400-pound gorilla will be the Longhorn release of Windows with a built-in true Hypervisor.
All of these hardware virtualization products have immense potential benefits, in provisioning speed, flexibility, Disaster Recovery support, etc. What is less clear is the economics of virtualization. People aren’t thinking through the economics of virtualization, partly because their initial focus is on the checks they have to write today, typically for computer hardware, and partly because the virtualization vendors are selling savings that do not yet materialize in the real world.
This is not to say that significant money cannot be saved by virtualization. If you have servers running at 5 to 8 percent CPU utilization, virtualization lets you get them to 60 to 70 percent utilization. There’s a very real initial cost savings on the hardware front. A two or four processor Intel box virtualized is certainly less expensive than eight single-processor boxes. So the first check you write in the virtualization process is certainly smaller. As well, you will achieve real savings in cabling costs, data center floorspace, and ongoing electric power consumption.
However, there are many other costs to virtualization that also must be brought into the equation. These have been largely ignored in the hype of selling virtualization.
First, there’s the virtualization software license. VMware ESX is not cheap. A high-end version of ESX, running on a four processor box, will cost close to $20,000 over a four-year period. Once the open source alternative Xensource and Microsoft Hypervisor become more prevalent, this cost will go down. But overall, simply consolidating 10 standalone servers into one virtual server will not bring your upfront expenditures down as much as the hardware alone might indicate.
The big overlooked cost in most virtualization analyses is the daily operations cost. The operating costs of any IT environment are largely driven by the number of operating system (OS) instances in the environment, not the number of servers. Although the IT staff monitors every server, they also monitor each and every OS and application. They patch the machines and fend off viruses and worms. So depending on what is virtualized, moving to a virtual environment may, or may not, save money.
Virtualizing on bare metal, which is the VMware approach, means that within each virtual partition a separate OS is loaded. So 10 OSs on 10 physical computers are still 10 OSs in the ESX server. Except it is really 11 OSs because ESX itself is an operating system that needs to be managed. The moral, of course, is if you don’t reduce the number of OSs, virtualization will not drive daily operating costs down.
For IT departments who maintain business as usual, migrating to a virtual environment may save 15 percent over a four-year period, with the up-front hardware savings being eaten away by the cost of virtualization software and the ongoing operations cost. One of the hidden costs that actually increase in a virtualized environment is the backup/recovery cost, due to the increased complexity of backing up multiple OSs through a single physical server’s infrastructure. Another complexity may come in if operations relies on certain technologies, such as layer 2 network separation, that are immature currently in a virtualized environment. Similarly, troubleshooting and performance analysis tools that operate on a physical basis, i.e. HBA throughput, physical disk I/O, do not tell the whole story in a virtualized environment, where many OSs are sharing the physical computer components. The big opportunity in virtualization comes when IT operations can behave differently than it does with standalone servers.
Typically, in a non-virtualized environment, much care and time is devoted to backing up and monitoring each and every server. However, if you have a development box, then maybe it doesn’t need to be backed up to tape and the data stored in a costly off-site vault. Since a virtualized OS is just a file, IT can snapshot the OS, back that snapshot up to disk on a daily basis and provide a means to restore the file as needed (essentially re-imaging the OS instance). Once IT takes a different approach, then costly tape drives, media and Iron Mountain expenses are replaced by less expensive alternatives. Modifying how IT performs monitoring, patching, and other routine activities can also dramatically reduce the ongoing cost of operations.
While this approach is not appropriate for a production environment where high availability, immediate response and performance management are mandatory, it can make a huge difference in a development environment. By modifying IT operations in a virtualized environment, up to 70 percent of the cost of a traditional non-virtualized environment can be eliminated.
In the near future, virtualization will proliferate in development environments where more cost effective operations make virtualization cost effective. As virtualization becomes more prevalent and the software gets cheaper, virtualized environments will mushroom even more than they are today. We will be “back to the future” in the multiplication of new OS instances, similar to where we were with Windows servers eight years ago. This, in itself, will present a new level of challenge to IT departments since each virtual OS will demand its own care and management, overwhelming IT’s ability to respond unless all of the costs are thought through.
Dave Leonard
CTO Infocrossing
Dave Leonard is chief technology officer of Infocrossing (IFOX on the NASDAQ), a fast-growing, publicly traded provider of selective IT infrastructure, enterprise application and business process outsourcing solutions headquartered in Leonia, N.J. Infocrossing’s services are built upon the strength of the company’s award-winning data centers located nation-wide and a world-class team of more than 700 IT professionals bringing unmatched expertise and best practices that offer Infocrossing clients a competitive advantage.
|
